In the case of a pay television broadcasting, several intervening parties cooperate so that the subscribers can receive the desired emissions.
Amongst these intervening parties we find firstly the main or national operators who offer the important television channels. It should be known that a same channel can be offered by more than one national operator. These national operators can either be the creators of this channel or they can sign broadcasting contracts with other local or foreign broadcasters. These national operators thus offer a service palette to local operators, the latter being connected to a certain number of subscribers.
A local operator can be active in several regions and the contracts binding this operator to a national operator are generally based on the number of subscribers to which the channel will be broadcasted or according to a geographical definition. Thus it is possible for a local operator to sign a broadcasting contract for a region A although this operator broadcasts also in regions B and C. Then it exists technically a possibility for this operator to also broadcast in the regions B and C without the national operator being able to intervene.
This is particularly the case in the case that the illegally broadcasted channel in the region B is also offered by another national operator through another local broadcaster. It is then difficult for the main operator to know if the signal received in the region B comes from a contract signed only for the region A or if it comes from another national operator. In fact, each subscriber can be connected to more than one local operator, the latter being supplied by many national operators.
It is well known that the national operators transmit their signals to the local operators in encrypted form. For the decryption operation, decryption devices are supplied by the national operator. These devices can include a decryption module and a smart card, the latter being in charge of ensuring the access control. Once the signal is decrypted by the decryption device, the local operator can dispose of it as it likes. It is then allowed for the local operator to compose its television bouquet with a selection of channels subscribed from several national operators.